package com.talent.aio.examples.im.common.utils;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class DesUtils {

    private static byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };

    public static String encrypt(String encryptString, String encryptKey) throws Exception {
        IvParameterSpec zeroIv = new IvParameterSpec(iv);
        SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
        byte[] encryptedData = cipher.doFinal(encryptString.getBytes());
        return Base64.encode(encryptedData);
    }

    public static String decrypt(String decryptString, String decryptKey) throws Exception {
        byte[] byteMi = Base64.decode(decryptString);
        IvParameterSpec zeroIv = new IvParameterSpec(iv);
        SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES");
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
        byte decryptedData[] = cipher.doFinal(byteMi);

        return new String(decryptedData);
    }

    /**
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub
        String key = "fdsfeofa";
        String text = "123ddddddddddddd45678";
        String result1 = DesUtils.encrypt(text, key);
        String result2 = DesUtils.decrypt(result1, key);
        System.out.println(result1);
        System.out.println(result2);
    }

    public static class Base64 {

        private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();

        /**
         * data[]进行编码
         * 
         * @param data
         * @return
         */
        public static String encode(byte[] data) {
            int start = 0;
            int len = data.length;
            StringBuffer buf = new StringBuffer(data.length * 3 / 2);

            int end = len - 3;
            int i = start;
            //			int n = 0;

            while (i <= end) {
                int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff) << 8) | (((int) data[i + 2]) & 0x0ff);

                buf.append(legalChars[(d >> 18) & 63]);
                buf.append(legalChars[(d >> 12) & 63]);
                buf.append(legalChars[(d >> 6) & 63]);
                buf.append(legalChars[d & 63]);

                i += 3;

                //				if (n++ >= 14) {
                //					n = 0;
                //					buf.append(" ");
                //				}
            }

            if (i == start + len - 2) {
                int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8);

                buf.append(legalChars[(d >> 18) & 63]);
                buf.append(legalChars[(d >> 12) & 63]);
                buf.append(legalChars[(d >> 6) & 63]);
                buf.append("=");
            } else if (i == start + len - 1) {
                int d = (((int) data[i]) & 0x0ff) << 16;

                buf.append(legalChars[(d >> 18) & 63]);
                buf.append(legalChars[(d >> 12) & 63]);
                buf.append("==");
            }

            return buf.toString();
        }

        /**
         * 将二进制转换成16进制
         * 
         * @param buf
         * @return String
         */
        public static String parseByte2HexStr(byte buf[]) {
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < buf.length; i++) {
                String hex = Integer.toHexString(buf[i] & 0xFF);
                if (hex.length() == 1) {
                    hex = '0' + hex;
                }
                sb.append(hex.toUpperCase());
            }
            return sb.toString();
        }

        public static byte[] decode(String s) {

            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            try {
                decode(s, bos);
            } catch (IOException e) {
                throw new RuntimeException();
            }
            byte[] decodedBytes = bos.toByteArray();
            try {
                bos.close();
                bos = null;
            } catch (IOException ex) {
                System.err.println("Error while decoding BASE64: " + ex.toString());
            }
            return decodedBytes;
        }

        private static void decode(String s, OutputStream os) throws IOException {
            int i = 0;

            int len = s.length();

            while (true) {
                while (i < len && s.charAt(i) <= ' ')
                    i++;

                if (i == len)
                    break;

                int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));

                os.write((tri >> 16) & 255);
                if (s.charAt(i + 2) == '=')
                    break;
                os.write((tri >> 8) & 255);
                if (s.charAt(i + 3) == '=')
                    break;
                os.write(tri & 255);

                i += 4;
            }
        }

        private static int decode(char c) {
            if (c >= 'A' && c <= 'Z')
                return ((int) c) - 65;
            else if (c >= 'a' && c <= 'z')
                return ((int) c) - 97 + 26;
            else if (c >= '0' && c <= '9')
                return ((int) c) - 48 + 26 + 26;
            else
                switch (c) {
                    case '+':
                        return 62;
                    case '/':
                        return 63;
                    case '=':
                        return 0;
                    default:
                        throw new RuntimeException("unexpected code: " + c);
                }
        }

    }

}